Epoxy functional compounds and systems are known in this art and employed in a wide range of applications and formulations. By “epoxy functional system” it is meant to refer to a mixture or blend containing at least one epoxy functional compound and at least one curing agent for the compound. Examples of such systems comprise automotive and industrial adhesives/sealants, corrosion resistance coatings, films and paints, pre-preg, tapes, and hand lay-up structural composites, powder coatings/films/paints, adhesives, films, among other applications.
It is known in this art to employ curing agents to affect or control cross linking of epoxy functional compounds. Conventional epoxy curing agents include amines, polyamides, dicyandiamide, polysulfides, anhydrides, melamines, ureas, imidizole compounds, amidoamines, phenol/formaldehydes, boron trifluoride complexes, among other conventional curing agents. Formulations containing such epoxy curing agents can be heat activated. While these curing agents are effective at curing epoxy functional compounds, formulations containing these curing agents can have decreased shelf stability when catalysts are included (e.g., catalysts to decrease activation temperature), are incompatible with many types of fillers, produce either relatively soft or rough surfaces, can cause paint staining, dark or discolored film, shrinkage of the compound, among other undesirable characteristics. Epoxy functional systems such as coatings, films, adhesives, among others, that employ conventional curing agents also suffer these negative characteristics. Conventional curing agents may also be environmentally undesirable.
There is a need in this art for a curing agent for an epoxy functional system that results in a cured system having improved shrinkage, clear or no color, lower curing temperature, shelf stability, less charring, increased hardness, reduced paint staining, among other properties not achieved by conventional curing agents.